feat(android): promote the low-latency pipeline to default

The async decode loop (burst-feed + present-newest-per-vsync, the Apple client's discipline) plus the per-SoC tuning was gated behind an experimental, default-off toggle after the 5dc24a0 overhaul regressed on some phones. That regression was the receive-side latency ratchet the async loop fed — a standing queue that only grew — now fixed in the shared core (FrameChannel jumps to live instead of accumulating it), so the fast pipeline is the default again. Default the master toggle on via a fresh pref key (low_latency_mode_v2), mirroring the migration da376b31 used to flip it off: a new key re-defaults every install — including ones persisted off under the old key — to on, so the promotion reaches users who had saved settings, not just fresh installs. Both stale keys are abandoned unread. Toggle-off still restores the original synchronous decode pipeline byte-for-byte as a per-device escape hatch. Drop "(experimental)" from the settings labels and fix the now-stale default-off wording in the native + Kotlin docs. No decode-path routing change — run_async is reached simply because the toggle now defaults on. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-07 16:18:40 +00:00
parent a1b890ef42
commit 04302075b5
5 changed files with 39 additions and 31 deletions
@@ -327,7 +327,7 @@ private fun buildSettingsRows(s: Settings, update: (Settings) -> Unit): List<GpR
        ) { update(s.copy(hdrEnabled = it)) },
        toggle(
            "lowLatency", null, "Low-latency mode",
-            "Experimental — aggressive decoder and system tuning. Turn off if the stream stutters or glitches.",
+            "The fast pipeline (async decode + system tuning). On by default — turn off to fall back if the stream stutters or glitches.",
            s.lowLatencyMode,
        ) { update(s.copy(lowLatencyMode = it)) },

@@ -55,14 +55,18 @@ data class Settings(
     */
    val libraryEnabled: Boolean = true,
    /**
-     * "Low-latency mode (experimental)" — the master switch over the latency overhaul: decoder
-     * ranking + per-SoC vendor keys + the async decode loop (native), pipeline thread boosts + ADPF
-     * max-performance, game-tagged AAudio, DSCP marking on the media sockets, HDMI ALLM, and the
-     * forced TV mode switch. (The Wi-Fi locks are NOT part of this — both are always held while
-     * streaming; see StreamScreen.) Off (default): the original decode pipeline, kept as the
-     * known-good baseline until the aggressive stack is proven per-device.
+     * "Low-latency mode" — the master switch over the latency pipeline: the async decode loop
+     * (native; burst-feed + present-newest-per-vsync, the Apple client's discipline), decoder ranking
+     * + per-SoC vendor keys, pipeline thread boosts + ADPF max-performance, game-tagged AAudio, DSCP
+     * marking on the media sockets, HDMI ALLM, and the forced TV mode switch. (The Wi-Fi locks are NOT
+     * part of this — both are always held while streaming; see StreamScreen.) On (default): the fast
+     * pipeline. Off restores the original synchronous decode loop byte-for-byte, kept as a per-device
+     * escape hatch. Promoted to default once the receive-side latency ratchet the overhaul interacted
+     * badly with was fixed in the shared core — the pump now jumps to live on a standing backlog
+     * instead of accumulating it (see `punktfunk-core` `FrameChannel`), so the async loop no longer
+     * feeds a queue that only grows.
     */
-    val lowLatencyMode: Boolean = false,
+    val lowLatencyMode: Boolean = true,
    /**
     * Wake-on-LAN a saved host before connecting when it isn't currently seen on mDNS. On (default):
     * a connect to a host with a learned MAC that isn't advertising sends a magic packet and waits
@@ -100,7 +104,7 @@ class SettingsStore(context: Context) {
            ?: if (prefs.getBoolean(K_TRACKPAD, true)) TouchMode.TRACKPAD else TouchMode.POINTER,
        gamepadUiEnabled = prefs.getBoolean(K_GAMEPAD_UI, true),
        libraryEnabled = prefs.getBoolean(K_LIBRARY, true),
-        lowLatencyMode = prefs.getBoolean(K_LOW_LATENCY, false),
+        lowLatencyMode = prefs.getBoolean(K_LOW_LATENCY, true),
        autoWakeEnabled = prefs.getBoolean(K_AUTO_WAKE, true),
    )

@@ -142,12 +146,16 @@ class SettingsStore(context: Context) {
        const val K_LIBRARY = "library_enabled"

        /**
-         * Deliberately NOT the original `"low_latency_mode"` key: that one shipped default-ON, so
-         * any install that ever saved settings persisted `true` — under the old key, flipping the
-         * default to off would leave exactly the regressed devices stuck on the overhaul. The fresh
-         * key restarts everyone at the safe default; the stale one is abandoned unread.
+         * Bumped AGAIN to restart every install at the new default (ON). History: the original
+         * `"low_latency_mode"` shipped default-ON; `"low_latency_mode_experimental"` restarted
+         * everyone at OFF after the overhaul regressed on some phones. That regression was the
+         * receive-side latency ratchet the async loop fed (a standing queue that only grew) — now
+         * fixed in the shared core (`punktfunk-core` `FrameChannel`: the pump jumps to live on a
+         * standing backlog instead of accumulating it), so the fast pipeline is the default again. A
+         * fresh key re-defaults every install — including ones persisted OFF under the old key — to
+         * on; both stale keys are abandoned unread. The toggle stays as a per-device escape hatch.
         */
-        const val K_LOW_LATENCY = "low_latency_mode_experimental"
+        const val K_LOW_LATENCY = "low_latency_mode_v2"
        const val K_AUTO_WAKE = "auto_wake_enabled"

        /** Legacy Boolean the enum replaced — read once as the migration default, never written. */
@@ -326,10 +326,10 @@ private fun DisplaySettings(s: Settings, update: (Settings) -> Unit, context: an
        ) { c -> update(s.copy(compositor = c)) }

        ToggleRow(
-            title = "Low-latency mode (experimental)",
-            subtitle = "Aggressive decoder and system tuning (per-device decoder selection, async " +
-                "decode, HDMI game mode). Can lower latency, but may stutter or glitch on " +
-                "some devices — turn off if the stream misbehaves.",
+            title = "Low-latency mode",
+            subtitle = "The fast pipeline (async decode, per-device decoder selection, HDMI game " +
+                "mode). On by default — turn off to fall back to the plain decode path if the stream " +
+                "stutters or glitches on this device.",
            checked = s.lowLatencyMode,
            onCheckedChange = { on -> update(s.copy(lowLatencyMode = on)) },
        )
@@ -65,10 +65,10 @@ fun StreamScreen(handle: Long, micEnabled: Boolean, onDisconnect: () -> Unit) {
    var showStats by remember { mutableStateOf(initialSettings.statsHudEnabled) }
    // Touch model is fixed per session (re-keys the gesture handler below if it ever changes).
    val touchMode = initialSettings.touchMode
-    // "Low-latency mode (experimental)" master toggle, resolved once for the session. Off (the
-    // default) runs the original decode pipeline; on enables the aggressive stack — decoder
-    // ranking + vendor keys + async loop (native side), HDMI ALLM below, game-tagged audio, and
-    // DSCP marking (applied earlier, at connect).
+    // "Low-latency mode" master toggle, resolved once for the session. On (the default) enables the
+    // fast pipeline — decoder ranking + vendor keys + async loop (native side), HDMI ALLM below,
+    // game-tagged audio, and DSCP marking (applied earlier, at connect); off falls back to the
+    // original synchronous decode pipeline as a per-device escape hatch.
    val lowLatencyMode = initialSettings.lowLatencyMode
    // TV form factor (leanback): the decoder actively switches the HDMI output mode to the stream
    // refresh; a phone/tablet gets the softer seamless frame-rate hint instead.